Floorings may be made of hard wood floorboards or laminate panels made from a derived timber product, in particular a highly compressed medium or high-density fiberboard.
Floorings are generally made of elongated floorboards or boards, with a top decorative surface, a bottom opposite surface and peripheral edges In particular; the edges have a connecting profile for the purpose of connecting adjacent boards and form the flooring.
A treatment can be applied to the peripheral edges of each floorboard, for instance in order to prevent the penetration of moisture and bacteria, which can cause the boards to swell up or mould to appear.
Different methods in the field of floorboard treatment have been disclosed in U.S. Pat. No. 2,431,225 (BELK); US patent applications published under Nos. 2002/0023702 A1 (KETTLER), 2002/0152714 A1 (VAN CAPELLEVEEN), US 2006/0037270 A1 (NIESE) or European patent application published under No. EP 2 127 807 (DELLE VEDORE).
Whilst the top and bottom surfaces of boards are generally provided with a very stable and wear-resistant coating which is also largely moisture proof, the unprotected derived timber material is exposed at the edges which are usually cut and profiled. Moisture can therefore penetrate at this point and cause swelling in a floorboard because the derived timber material that is used is relatively hygroscopic.
Floorboards being generally hydroscopic, any change in the relative humidity of the surrounding atmosphere leads to a change in the boards' shape after installation i.e. shrink or swell, and a gap between the boards will appear, rendering these edges permanently visible.
Some board models have profiled tapered edges. Two adjacent boards will then form a groove along two connected edges. This groove is commonly named “micro-V” in the art of flooring.
The flooring will become unsightly when gaps and micro-Vs between the floorboards are particularly visible, in particular when the peripheral edges have a different color or shade than the top surfaces of the boards. This difference may be due to the fact that the edges have not been treated. Furthermore, the top surface may have its color fading with the passing of time, surface wear or both.
Although top surfaces and tapered edges of the boards are manufactured or treated with a same color and shade, a shadow effect will render the shade of the micro-V apparently darker than the shade of the top surface.
A solution to the problems described above would be to have the peripheral edges treated or dyed in a way to obtain a shade of the edges slightly lighter than the shade of the top surfaces. The shades will be selected by the manufacturer in order to have edges and surfaces appearing with a same shade, once the boards are assembled to form the flooring. And despite the shadow effect or the color fading of the top surfaces.
Boards with the above-described properties can be treated manually. However, this method is not economically profitable for a mass-production of boards, except in countries providing cheap labour.